PARENT COMPANY FINANCIAL INFORMATION - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets:
Cash and cash equivalents	$ 137,684	$ 89,736
Other	44,987	38,741
Total assets	5,152,760	3,941,863	$ 3,003,986
Liabilities and Stockholders' Equity:
Subordinated debentures	144,592	80,678
Borrowed funds	4,647	5,354
Other	22,980	17,649
Liabilities and Equity, Total	5,152,760	3,941,863
Parent Company [Member]
Assets:
Cash and cash equivalents	67,231	5,941
Investment in subsidiary bank	720,159	616,807
Investments in statutory trusts	496	496
Bank owned life insurance	4,202	4,200
Other	2,659	2,292
Total assets	794,747	629,736
Liabilities and Stockholders' Equity:
Subordinated debentures	144,592	80,678
Borrowed funds	4,647	5,354
Other	693	46
Stockholders' equity	644,815	543,658
Liabilities and Equity, Total	$ 794,747	$ 629,736